body {
  background: var(--bg);
}

.sim-shell {
  max-width: 960px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

.sim-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.2rem;
}

.sim-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.2rem;
  box-shadow: var(--shadow);
}

.sim-card h3 {
  margin: 0 0 0.6rem;
}

.sim-form label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.sim-form input,
.sim-form select {
  width: 100%;
  padding: 0.6rem 0.8rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  margin-bottom: 1rem;
}

.sim-result {
  margin-top: 1rem;
  padding: 0.8rem 1rem;
  border-radius: 12px;
  background: var(--surface-alt);
}

.sim-nav {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}